I know this post is quite old but I have just gotten around to setting up my new MM setup, not sure if filtering can be done with the standard calendar but it is possible with the module ‘MMM-CalendarExt2’.

With this example I am able to filter out events that have ‘birthday’ in the title:

filter: (event) =>{
  if (event.title.search(“Birthday”) > -1) {
    return true
  } else {
    return false
  }
},

On my setup I am importing 3 ics files and the displaying different views on my screen, one of them is a list of birthdays from three calendars.

Let me know if you need more info.

Cheers

Nathan